David Roberts

In late July 1776, fathers Francisco Atanasio Domínguez and Francisco Vélez de Escalante set out from Santa Fe to chart a route to the new Spanish missions in California. The Fransiscans planned to scout the country for mineral wealth and locate the Ute and Navajo tribes for conversion. In present- day Utah, however, the dangers of starvation and hypothermia forced them to turn back. By November the friars were reduced to survival mode: stymied by the raging Colorado River, they had to kill their horses for food.

David Roberts has spent his career documenting voyages to the most extreme landscapes on earth. In his new book, “Limits of the Known,” he reflects on humanity’s—and his own—relationship to extreme risk; and he tries to make sense of why so many have committed their lives to the pursuit of adventure.